Hi Rob,
Hmmmm I don't think you can actually
scan a planisphere.
It's a moving/rotating board where you select & turn for the corresponding time and month to show what's in the sky.
Their quite cheap to buy- Australian Sky & Telescope on-line sell them, as do Bintel and Andrews Communictions, for around $13.
The Australian Sky & Telescope magazine also has a monthly sky map in it which may be of use if you're after just a map of the sky.